Hello,
I followed the first tutorial, but the JAR-File won't run. After I had clicked "
Generate ant build.xml and run", the program "javaw.exe" wasn't set as default for opening the JAR-File. After I clicked Open with -> Javac.exe, nothing happened.

Yes, sorry, I meant "javaw.exe". But anyway, I fixed the prblem myself: It was not the fault of e(fx)clipse, there was just something wrong with my Java-Installation. But after I jused Jarfix (http: //johann.loefflmann.net/de/software/jarfix/index.html -> without the blank), everything was fine.